Kennedy MJ, Scripture CD, Kashuba AD, Scott CS, Gaedigk A, Kearns GL. Activities of cytochrome P450 1A2, N-acetyltransferase 2, xanthine oxidase, and cytochrome P450 2D6 are unaltered in children with cystic fibrosis. Clin Pharmacol Ther. 2004 Mar; 75(3):163-71.